Windows
OS:Windows Vista
Processor:2 GHz Dual Core 
Memory:2 GB RAM
Graphics:NVIDIA GeForce 8600 GT / ATI Radeon HD 2600 XT or greater 
DirectX®:9.0
Hard Drive:20 GB HD space
Sound:DirectX Compatible
Other Requirements:Broadband Internet connection
Additional:Initial installation requires one-time internet connection for Steam authentication; software installations required (included with the game) include Steam Client, Visual C++ 2008 Redistributable, DirectX and Microsoft .NET 4.